ImmediateEncoding.cc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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    The above copyright notice and this permission notice shall be included in
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/**
 * @file ImmediateEncoding.cc
 *
 * Implementation of ImmediateEncoding class.
 *
 * @author Lasse Laasonen 2005 (lasse.laasonen-no.spam-tut.fi)
 * @note rating: red
 */
 
#include <string>
 
#include "ImmediateEncoding.hh"
#include "SourceField.hh"
#include "Application.hh"
#include "ObjectState.hh"
 
using std::string;
 
const std::string ImmediateEncoding::OSNAME_IMM_ENCODING = "imm_encoding";
const std::string ImmediateEncoding::OSKEY_IMM_WIDTH = "imm_width";
 
/**
 * The constructor.
 *
 * Registers the encoding automatically to the parent source field.
 *
 * @param encoding The encoding for inline immediates.
 * @param extraBits The number of extra bits in the encoding.
 * @param immediateWidth Width of the inline immediate.
 * @param parent The parent source field.
 * @exception ObjectAlreadyExists If the given source field has an immediate
 *                                encoding already or if the encoding is
 *                                ambiguous with some socket or bridge
 *                                encoding in the source field.
 * @exception OutOfRange If the given immediate width is negative.
 */
ImmediateEncoding::ImmediateEncoding(
    unsigned int encoding, unsigned int extraBits, int immediateWidth,
    SourceField& parent)
    : Encoding(encoding, extraBits, NULL), immediateWidth_(immediateWidth) {
    if (immediateWidth < 0) {
        throw OutOfRange(__FILE__, __LINE__, __func__);
    }
 
    parent.setImmediateEncoding(*this);
    setParent(&parent);
}
 
/**
 * The constructor.
 *
 * Loads the state of the object from the given ObjectState instance.
 *
 * @param state The ObjectState instance.
 * @param parent The parent source field.
 * @exception ObjectAlreadyExists If the given source field has an immediate
 *                                encoding already or if the encoding is
 *                                ambiguous with some socket or bridge
 *                                encoding in the source field.
 * @exception ObjectStateLoadingException If the given ObjectState instance
 *                                        is erroneous.
 */
ImmediateEncoding::ImmediateEncoding(
    const ObjectState* state, SourceField& parent)
    : Encoding(state, NULL) {
    const string procName = "ImmediateEncoding::ImmediateEncoding";
 
    if (state->name() != OSNAME_IMM_ENCODING) {
        throw ObjectStateLoadingException(__FILE__, __LINE__, procName);
    }
 
    try {
        immediateWidth_ = state->intAttribute(OSKEY_IMM_WIDTH);
        if (immediateWidth_ < 0) {
            throw OutOfRange(__FILE__, __LINE__, __func__);
        }
    } catch (const Exception& e) {
        throw ObjectStateLoadingException(
            __FILE__, __LINE__, __func__, e.errorMessage());
    }
 
    parent.setImmediateEncoding(*this);    
    setParent(&parent);
}
 
/**
 * The destructor.
 */
ImmediateEncoding::~ImmediateEncoding() {
    SourceField* oldParent = parent();
    assert(oldParent != NULL);
    setParent(NULL);
    oldParent->unsetImmediateEncoding();
}
 
 
/**
 * Returns the parent source field.
 *
 * @return The parent.
 */
SourceField*
ImmediateEncoding::parent() const {
    InstructionField* parent = Encoding::parent();
    if (parent != NULL) {
        SourceField* sField = dynamic_cast<SourceField*>(parent);
        assert(sField != NULL);
        return sField;
    } else {
        return NULL;
    }
}
 
 
/**
 * Returns the immediate width.
 *
 * @return The immediate width.
 */
int
ImmediateEncoding::immediateWidth() const {
    return immediateWidth_;
}
 
 
/**
 * Returns the encoding width.
 *
 * @return The encoding width.
 */
int
ImmediateEncoding::encodingWidth() const {
    return Encoding::width();
}
 
 
/**
 * Returns the position of the immediate encoding.
 *
 * @return The position of the immediate encoding.
 */
int
ImmediateEncoding::encodingPosition() const {
    if (parent()->componentIDPosition() == BinaryEncoding::LEFT) {
        return parent()->width() - parent()->extraBits() - encodingWidth();
    } else {
        return 0;
    }
}
 
 
/**
 * Returns the position of the short immediate within the source field.
 *
 * @return The position of the short immediate.
 */
int
ImmediateEncoding::immediatePosition() const {
    if (parent()->componentIDPosition() == BinaryEncoding::LEFT) {
        return 0;
    } else {
        return parent()->width() - parent()->extraBits() - immediateWidth();
    }
}
 
 
/**
 * Returns always 0.
 *
 * @return The position of the encoding.
 */
int
ImmediateEncoding::bitPosition() const {
    return 0;
}
 
 
/**
 * Returns the width of the encoding + immediate width.
 *
 * @return The width.
 */
int
ImmediateEncoding::width() const {
    return immediateWidth() + encodingWidth();
}
 
 
/**
 * Saves the state of the object to an ObjectState instance.
 *
 * @return The newly created ObjectState instance.
 */
ObjectState*
ImmediateEncoding::saveState() const {
    ObjectState* state = Encoding::saveState();
    state->setName(OSNAME_IMM_ENCODING);
    state->setAttribute(OSKEY_IMM_WIDTH, immediateWidth());
    return state;
}